Pressure release valve for battery cells



July 29, 1958 E. RQST,

PRESSURE RELEASE VALVE' FOR BATTERY CELLS Filed Jan} 27, 1955 5 w 2 8 .WM w 7. 8 A 30 5 3. 12 7 1 =3 7 +h w|| u 4 I 3 k 7 z a w 9 aa l 3 a 0 (l. *2 Mm!\ INVENTOR BY "rwe..s'2.$v R0515 i Haw United States Patent PRESSURE RELEASE VALVE FOR BATTERY CELLS Ernest Rost, Morristown,'N. 1., assignor, by mesne assign= ments, to McGraw-Edison Company, Elgin, 11]., a corporation of Delaware This invention relates to a pressure release valve of novel construction adapted especially for the ffiller opening of a mine lamp battery.

The valve is provided with depressible means which when in a free state will cause the valve to release at a predetermined lower cell pressure and which when .depressed as by closing the. cover of the battery container will cause the valve to be either substantially sealed or :to have pressure release at a substantially higher pres- .sure.

.An object of the invention is to provide such a vaflve in a simple, dependable form which will not stick or clog .from corrosion of parts due to contact with .the

battery electrolyte.

.appended claims.

In the description of my invention reference :18 :had to'the accompanying drawings, of which:

Figure 1 is an enlarged sectional view of avalve according to my invention, taken through the central axis thereof as on the line 1--1 of Figure 3;

Figure 2 is a fractional section on the line 2-2 of Figure 1;

Figure 3 is a fractional plan view of a top portion of a mine lamp battery showing a removable block carrying a group of filler-opening valves for the cells of the battery; and

Figure 4 is a fractional side elevation of such battery showing the cover in open position.

A battery for mine lamps is typically housed in an oblong container made for example 'of plastic and having a heavy metal band 11 at the top provided with an inturned lip or flange 12 which embraces a rim flange 13a of a heavy lid structure 13, also of plastic, to hold the lid tightly sealed to the top edge of the container. Such battery comprises a plurality of vertically-disposed cells 14 of which there are typically four placed in two rows, one row of which along the width dimension of the case appears in Figure 4. The cells have individual filler tubes 15 flanged at the bottom and threaded at the top. These tubes are grouped in proximity to each other at the upper central portion of the battery. The lid has a wide transverse slot 16. In the bottom wall 16a of this slot there are four openings 17 through which extend the respective filler tubes. Threaded on the outer ends of the filler tubes are circular nuts 18 which clamp the wall 16a against the bottom flanges of the tubes.

Fitting the slot 16 is a block 19 having four mounting p 2,845,090 Patented July 29, 1958 .holes 20 for respective filler-opening valves each generally referred to .as 21. Each mounting holeis recessed at the bottomto receive an annular mounting flange 22 of the respective valve structure and each valve has a tubular nipple 23 depending below the flange and surrounded by a sealing washer 24 of yieldahle material. As the block is installed in place the valves are mounted as a unit with the nipples thereof telescoping respectively with the filler tubes -15 and with the sealing washers being interposed between the respective mounting flanges 22 and top edges of the filler tubes. At the center of the block there 'is a clampingscrew 25 which threads into the wall 16a of the lid "to exert clamping pressure on the sealing washers 24 wherefore to seal the valves 21 to the respective filler tubes'15.

Each valve has a valve structure comprising a tubular member 26 provided with the flange22 .and depending nipple 23 at the bottom, and having a central portion above the flange 22 and a head portion .26aat the top. This tubular member has a large here 2.7 leading from the bottom to the head portion and has .a relatively small bore 28 extending onwardly through the head portion. The end surface of the tubular member surrounding the bore 28 forms a valve seat, .as will appear. 'In the central portion of this tubular member there is a cross slot 29, formed as ,by a saw cut, which is closed by a heavy .sleeve'30 of yieldable material such as rubber, the sleeve being in a suitably stretched condition around the member 26 to provide for release of pressure through the .slot 29 .at a desired pressure, .as will appear. The .head 26a is covered by a .cap 31 also of yieldable ma- .terial such as rubber. .This cap ,has an .end wall 3.1a overlying the valve seat at the end of the tubular member, and has a surrounding .integral sleeve portion 31b mounted in a stretched condition around the head 26a. Additionally, the -.cap.has a hollow .frustoconical portion 31c extending above the wall 31w which is provided with .a central opening .32 at its upper end. Fitted into this .frustoconical portion is a plunger 33 having a cylindrical portion or .button 33a at the top extending into the opening .32 and having a frustoconical portion at the bottom embraced .by thefrustoconical wall 310 of the cap.

The valve structure abovedescribed is enclosed in a cylindrical shell 34 which is threaded at the bottom onto an annular shoulder 35 provided on the flange 22. The shell has a small opening 36 at the top and has a flared internal surface 37, formed as by a countersink. The button 33a and surrounding lip portion of the frustoconical wall 31c of the cap extend through the opening 36, and the inner flared wall 37 of the cap conforms to and engages under pressure the wall 310 to seal the shell to the cap. In a side wall of the shell there is an outlet opening 38 which is aligned with a respective slot 39 in the block 19 to provide for release of gas from the valve structure.

Secured to the lid structure 13 by a hinge 40 is a shallow cover 41. When this cover is depressed it is latched closed by a pawl 42 in the lid structure engaging a slotted latch plate 43 mounted on one or more studs 44in spaced relation to the under side of the cover. Such latches are typically releasable-only by magnetic means but need not be herein described for the purposes of the present invention. On the lid structure near the front of the battery there is a pair of charging terminals 45 which become enclosed when the cover is closed. Leading from the back side of the battery is a cable 46 for connecting the battery to a mine lamp or other suitable device. On the under side of a central portion of the cover there is a heavy pad 47 of yieldable material which comes to bear against the button 33a of each valve 21 to condition the valves to release at a higher pressure when the cover is closed.

Mine lamp batteries are recharged after each days use by mounting them in a suitable charging rack, opening the cover and connecting a generator to the charging terminals 45. During recharging the filler openings are kept closed, but it is necessary to allow for escape of gas at a suitable low pressure by the valves 21. A gaseous release at low pressure is provided via the bore 28 and a gap formed by the pressure between the external surface of the head 26a and the internal surface of the walls 31a and 31b of the cap 31, the released gas then passing through the outlet opening 38 and slot 39 to the atmosphere. When the battery is in use, it is necessary that it be kept closed insofar as is practically feasible in order to provide maximum protection for the user. Accordingly, the cover is then latched closed and the valve is set to release at a much higher pressurea pressure which will normally not be attained during use of the battery so that the cells are therefore eflfectively hermetically sealed. This setting of the valves to release at such higher pressure is accomplished by depressing the plungers 33 by the cover as the cover is closed. As the plungers are so depressed they press the wall 31a of the cap against the seat formed on the end of the tubular member 26 so as to retain the opening 28 hermetically sealed at pressures above the lower release pressure abovementioned. However, should the cell pressure build up to an undesirably high value the heavy sleeve 30 surrounding the tubular member 26 will yield to the gaseous pressure and allow a pressure release through the slot 29.

Heretofore, valves of the character described have used a shut-ofi valve between the two pressure release vents, which shut-off valve has been of ordinary type moved to closed position by the closing of the cover. In use, such shut-off valves tend to stick from corrosion of metal parts exposed to contact with the electrolyte of the cells of the battery, with the result that the release valves will not operate properly to release at different pressures when the battery cover is opened and closed. The present valve construction overcomes these difficulties by not exposing any movable metal parts to contact with the electrolyte. This is accomplished by sealing the plunger 33 from contact with the electrolyte and from contact with the released gases by encasing it in the surrounding rubber sheath 310 of the cap 31 and sealing the cap to the housing member 34 of the valve. In this construction the cap provides the desired pressure seal over the opening 28 when the plunger is depressed and provides also '4 the yieldable means to restore the plunger when the cover is opened.

The embodiment of my invention herein particularly shown and described is intended to be illustrative and not limitative of my invention since the same is subject to changes and modifications without departure from the scope of my invention, which I endeavor to express according to the following claims.

I claim.

1. A pressure release valve comprising a flanged tubular member adapted to fit the filler opening of a battery cell, said tubular member having an axial opening therethrough and provided with a valve seat at its outer end; a cap of yieldable material fitting over the outer end of said tubular member with its surrounding wall under tension to close said opening except at pressures sutficient to provide for escape of gas between said surrounding wall and tubular member; a plunger atthe outer end of said tubular member for pressing the end wall of the cap against said seat to seal said opening at pressures above said predetermined value; and extending integral wall on said cap embracing said plunger; and a cylindrical housing member secured to the flanged end of said tubular member and having an opening in the end wall through which extends an outer end portion of said plunger, said tubular member, plunger and housing member being metal parts, and said cap and extending integral wall comprising a sheath around said plunger and protecting it from metal-to-metal contact with the other of said metal parts.

2. The release valve set forth in claim 1 wherein said housing member has a flared inside wall embracing said cap under pressure to seal the housing member to the cap, and said'housing member has an outlet opening for escape of released gas therefrom.

References Cited in the file of this patent UNITED STATES PATENTS 460,714 Wolfe Oct. 6, 1891 480,400 Wolfe Aug. 9, l892 481,762 Ives Aug. 30, 1892 583,632 Roesch June 1, 1897 1,950,325 Punte Mar. 6, 1934 2,284,051 Gilbert May 26, 1942 2,294,785 Langdon Sept. 1, 1942 2,635,628 Stamper Apr. 21, 1953 

